Historically, flexible intermediate bulk containers (bulk bags) have been used for receiving, storing, transporting and discharging flowable materials of all types. Bulk bags are typically constructed in a square, vertically rectangular, or circular shapes with lift straps attached to each of the uppermost corners of the square, rectangle or circle.
By way of example, flexible intermediate bulk containers are used for handling granular, liquid or powder (flowable) materials such as chemicals, minerals, fertilizers, foodstuffs, grains and agricultural products. The advantages of such receptacles include relatively low weight, reduced cost, versatility and, in the case of reusable receptacles, low return freight costs.
At the present time most bulk bags are manufactured from woven polypropylene fabric. Typically, such containers are constructed by stitching or sewing together two or more sidewalls and a bottom wall. Optionally, a top wall and lift straps or other structural support can be added to the basic construction. The traditional method of securing the seams of the several portions of the container includes sewing or stitching.
The instant invention comprises a method of constructing a bulk bag from a tubular blank of woven fabric comprising side, top and bottom walls of which are quickly, easily and inexpensively joined to form the container.